APPARATUS AND PROCESS FOR PRODUCTION OF TIGHTS"

The present invention relates to an apparatus and a process for production of tights. In particular, though not exclusively, the present invention relates to the step of sewing the toes of the tights.

As is known, tights are produced starting from two tubular textile manufactures, which are loaded on a machine used as a line-closer; the machine comprises a carousel structure rotating about a vertical axis and provided with a plurality of special shapes. The two tubular manufactures that make up the tights are loaded on a pair of adjacent dummies, and in subsequent stations of the line-closer are subjected to a longitudinal cut at a portion thereof which in the finished product constitutes the trunk part and, thereafter, are sewn together at the previously-cut flaps.

Also known are machines, known as toe-closers, positioned downstream of the line-closer and having the task of closing the toe of each of the above-mentioned tubular products, i.e. at the toe of each leg of the tights.

Generally, a toe-closer comprises a plurality of support tubes of the products which are mounted in a turret that moves them between a loading upturning and positioning station, a station for adapting the toe to the curvature to be obtained for the sewing, a station in which the sewing is carried out and a final unloading station of the tights with the toes sewn.

Examples of line-closer and toe-closer machines are described, for example, in the Italian patent application FI2009A000207 and in patent documents GB 1501869 A and EP 0126800 A 1.

The Applicant has found that these machines, though enabling carrying out the closure of the toes of tights, are not free of drawbacks and can be improved in various aspects. In fact, the known solutions might not enable obtaining a "round" sewing, i.e. having an arc of circumference progression, and this can have an influence on the quality of the finished product, both from an aesthetic point of view and from a functional point of view, in terms of comfort when the tights are worn and/or working life of the sewing. Further, the known solutions might not be able to vary the shape and/or the length of the sewing of the toes of tights.

An aim of the present invention is to obviate one or more of the above-cited drawbacks.

A further aim of the invention is to provide an apparatus and a process for production of tights which enable realizing a sewing of the toes of tights, obtaining textile articles of high quality and substantially free of imperfections. A further aim of the invention is to provide an apparatus and a process for production of tights which enable selecting and/or easily and/or precisely regulating the shape of the sewing of the toes, for example in terms of shape and/or dimensions and/or radius of curvature.

A further aim of the invention is to provide an apparatus and a process for production of tights which enable reducing production waste.

A further aim of the invention is to provide is to provide an apparatus and a process for production of tights which enable adjusting the sewing of the toes of tights in relation to the type of tights and/or the desired characteristics for the sewing. A further aim of the invention is to provide an apparatus and a process for production of tights which enable selecting and/or regulating the shape and/or the dimensions of the sewing of the toes of tights independently of the denier size of tubular elements forming the tights and/or the dimensions of the toes of the tights.

A further aim of the invention is to provide an apparatus and a process for production of tights which enable obtaining productions of high uniformity levels among the various tights produced and/or obtaining a high productivity in terms of tights produced per unit of time.

A further aim of the invention is to provide an apparatus and a process for the production of tights which enable realising sewn seams in a simple and/or rapid and/or automatic and/or economical way.

A further aim of the invention is to provide an apparatus and a process for the production of tights which are simple, sturdy and economical to realize, even in terms of modest modifications with respect to apparatus of known type.

These and other aims, which will better emerge during the course of the following description, are substantially attained by an apparatus for the production of tights, and a process for using the machine, according to the appended claims, in any combination thereof.

Further characteristics and advantages will more fully emerge from the detailed description of a preferred but not exclusive embodiment, according to the appended figures, in which:

figure 1 illustrates a schematic view from above of an apparatus for production of tights according to the present invention;

figure 2 illustrates a portion of a possible embodiment of the apparatus of the present invention, in particular of the positioning means, in a first configuration;

figure 3 illustrates the portion of apparatus of figure 2, with the positioning means in a second configuration;

figure 4 illustrates a portion of a possible embodiment of the apparatus of the present invention, in particular of the blocking and transport device, in a first configuration;

figure 5 illustrates the portion of apparatus of figure 4, with the blocking and transport device in a second configuration;

figures 6 and 7 show two perspective views, respectively front and rear, of a portion of the apparatus of the present invention, in a possible embodiment thereof, in particular of the blocking and transport device, in a first configuration;

figures 8 and 9 illustrate two perspective views, respectively front and rear, of the portion of apparatus of figure 6 and 7, in a second configuration. With reference to the figures, reference numeral 1 denotes in its entirety an apparatus for production of tights according to the present invention. Figure 1 illustrates a schematic layout of the apparatus 1 according to the invention. In particular, a line-closer machine and a toe-closer machine are shown, reciprocally flanked. A transfer device is present between them for transfer of the semi-finished workpieces of tights between the line-closer and the toe- closer, not illustrated and for example of known type. In the figures, the parts of the apparatus 1 that are not explicitly shown can be of a known type, and therefore are not described in detail in the present description.

The apparatus 1 for production of tights comprises a line-closer machine 2 suitable for joining a pair of tubular textile fabrics to one another, forming a semi-finished piece having a trunk part and two legs with open toes, a toe-closer machine 3 suitable for sewing, by means of a sewing machine, the toes of the legs of the semi-finished piece, and a transfer device configured for transferring the semi-finished piece from the line-closer machine to the toe-closer machine. The sewing machine of the toe-closer (not shown) can be a sewing machine of the overlock cut and sew type, for example a machine of the type produced by the company UNION SPECIAL ® in one of the models of the 9M series or the like.

The line-closer machine preferably comprises a first rotating carousel and the toe-closer machine comprises a second rotating carousel, the first and second rotating carousels being synchronized with one another.

The toe-closer machine comprises a plurality of support tubes 4 of the semifinished pieces, the tubes being coupled two-by-two such that each pair of tubes 4 supports the legs of a same semi-finished piece. The tubes of the toe-closer are preferably all identical to one another. Each tube 4 is provided with two blades 5 arranged at sides of the tube and longitudinally movable, i.e. parallel to a longitudinal axis of the tube, between a retracted position, in which the blades 5 are comprised in a. longitudinal volume of the tube, and an advanced position, in which the blades are extracted longitudinally from the tube. Figure 3 shows the blades of a pair of tubes, combined with one another, in a retracted position, while figure 4 shows the same pair of tubes with the blades in an advanced position.

The apparatus 1 further comprises a blocking and transport device 6 active on the toes of the legs of a semi-finished workpiece so as to block them in a predetermined configuration and transport them to the sewing machine such that the toes are closed by performing a sewing having a predetermined progression. The blades 5 are in a retracted position when the semi-finished piece is transferred from the line-closer machine to the toe-closer machine and during the sewing of the toes, while they are in an advanced position when the toes are subjected to the blocking and transport device 6.

The blocking and transport device comprises a plate 7 positioned inferiorly of the tubes 4 and mobile between a lowered position, in which it does not cooperate with the semi-finished piece, and a raised position (at a substantially equal height to a horizontal central plane of the tubes), in which it enters into contact inferiorly with the toes of the semi-finished piece enveloped about the blades 5, arranged in an advanced position, of a pair of tubes. The blocking and transport device 6 further comprises at least a pair of pressers 8 solidly movable between a raised position, in which they do not contact the toes of the semifinished piece, and a lowered position, in which they each block a portion of a respective toe of the semi-finished piece, pressing the portion onto the underlying plate 7. Each presser 9 of the pair of pressers can assume at least a straight configuration, in which the presser causes the blocked portion of the respective toe to take on a linear shape and a curved configuration, in which the presser causes the blocked portion of the respective point to assume a curved shape. The curved shape substantially corresponds to the predetermined progression of the sewing.

The blocking and transport device 6 comprises movement means 9 configured such as to move the pair of pressers between a first position, in which the pressers can cooperate with the pair of tubes bearing the semi-finished piece, and a second position, in which the pressers present the toes to the sewing machine.

In the first position the pressers are preferably above the pair of tubes and in the second position they are laterally displaced with respect to the first position. In substance, the apparatus 1 is configured to carry out a machine cycle, in which:

- the transfer device transfers a semi-finished piece from the line-closer machine 2 to a pair of tubes 4 of the toe-closer machine 3, having the respective two blades 5 in a retracted position, such that the two legs having the open toes of the semi-finished piece are each enveloped about a respective tube;

- the two blades 5 of each tube 4 of the pair of tubes are brought into an advanced position, positioning the toes of the legs of the semi-finished piece beyond the longitudinal extension of the tubes;

- the plate 7 is brought from the lowered position into the raised position, inferiorly entering into contact with the toes of the semi-finished piece enveloped on the blades of the tubes;

- the two pressers 8 of the pair of pressers, in a raised position, are preferably together brought together into the curved configuration (i.e. in a synchronised time and/or space), into the curved configuration;

- the two pressers 8 of the pair of pressers are brought into the lowered position, each blocking a curved portion of a respective toe of the semifinished piece, pressing the curved portion on the underlying plate in the raised position;

- the two blades 5 of each of the two tubes 4 are returned into the retracted position;

- the two pressers 8 of the pair of pressers are brought, preferably together, into the straight configuration, causing the blocked portions of the toes to assume a linear shape;

- the movement means 9 position the pair of pressers 8 in the second sewing position, in which the toes are closed by means of the performing of a stitching having said predetermined progression;

- on completing the stitching of the toes, the semi-finished piece is unloaded from the respective pair of tubes 4, the movement means 9 position said pair of pressers in the first position, the pair of pressers 8 is brought into the raised position and the plate 7 is brought into the lowered position.

Each of the pressers 8 preferably comprises a deformable foil 10, preferably made of metal and/or a plastic material and/or rubber, arranged vertically and normally having a substantially straight development and corresponding to the straight configuration, the foil 10 possibly being curved, under the action of an appropriate solicitation, in such a way as to be brought reversibly into the curved configuration. Each presser 8 preferably comprises a respective actuator 1 1 operatively active on the respective foil 10 in such a way as to selectively exert the appropriate solicitation and determine the passage of the presser 8 from the straight configuration to the curved configuration

Figures 4 and 5 illustrate a portion of the toe-closer and the blocking and transport device, with some parts removed better to evidence the pressers 6 and the respective deformable foil. In particular, in figure 4 and in figure 5 the pressers are in a curved configuration, with the foils subjected to solicitation and therefore curved. The curvature is preferably obtained by pushing a central portion of the foil and keeping the two lateral ends of the foil blocked; in this way the foil, being unable to translate, reacts by deforming in the centre and assuming an overall curved conformation; the curvature is preferably symmetrical with respect to a centre of the foil.

Each foil 10 preferably comprises a sheet portion 10a, made of metal or plastic, for example a slim steel sheet, and a sealing portion 10b, inferiorly fixed to the sheet portion, preferably over a whole length thereof, and destined to enter into contact with the respective toe of the tights enveloped on the respective tube, the sealing portion being preferably made of rubber or plastic. In practice, the portion of sheet provides the foil with the necessary elasticity and the ability to reversibly pass between the straight and curved configurations, while the retaining portion enables effective blocking of the underlying portion of the toe of the tights, avoiding sliding thereof on the underlying plate and keeping the position fixed, up until the presser is in the lowered position, with respect to the presser.

The deformable foil 10 and the actuator are preferably structured such as to modify the curved configuration in such a way as to select the shape of the predetermined progression of the sewing. The actuator 1 1 is preferably a linear actuator, preferably a pneumatic piston, having a selectable pathway. The predetermined progression of the stitching is in a curved tract shape having a radius of curvature, and the dimension and/or the radius of the tract is a function of the travel of the linear actuator, which is selectable as required within an operating range.

The presser 8, when it is in the curved configuration and is brought into the lowered position, preferably blocks a portion of the respective toe of the semifinished piece corresponding to the portion destined to be sewn in order to obtain the predetermined progression of the sewing, and when it is in the lowered position and is brought into the straight configuration, stretches out the curved portion, previously blocked by the presser in a curved configuration, such as to proffer to the sewing machine a straight portion of toe corresponding to the curved portion.

In substance, the passage of the presser from the curved configuration to the straight configuration elastically straightens the portion of toe blocked by the presser such that the sewing occurs along a straight portion, and, at the same time, once the presser has been released, produces a curved stitching of the toe having a curved progression. The predetermined progression of the stitching corresponds substantially to an arc of circumference.

The movement means 9 preferably comprise an actuator 15 and a carriage 15a activated by said actuator and bearing a pair of pressers. The carriage enables translating the pressers, between the first and the second position, in a transversal direction and/or a perpendicular direction to the longitudinal development of the tubes.

The actuator preferably comprises a step motor and a transmission belt activated by the step motor, the belt bearing - fixed thereto - the groups of the two pressers.

Each tube 4 preferably comprises a support 16 connecting the two blades 5, arranged slidably at the sides of the tube, so as to solidly constrain them to one another. The toe-closer machine 3 preferably comprises positioning means 20 operatively activatable on a pair of tubes 4 bearing the semi-finished piece such as to move the blades 5 of the tubes together between the retracted position and the advanced position. The positioning means 20 preferably comprise a translating organ 21 configured such as to engage, in a positioning station of the toe-closer machine 3, the respective two supports 16 of a pair of tubes 4 located in the positioning station and such as to determine the advancing and retracting of the supports, in such a way as to move the blades of the tubes between the advanced position and the retracted position. The positioning means preferably comprise a respective actuator 22, preferably a pneumatic cylinder or a linear motor, operatively active on the translating organ 21. In substance, when a pair of tubes bearing a semi-finished workpiece of tights reaches the positioning station (in which the semi-finished workpiece is partially extracted from the tube - by the blades - so that the toes can be subjected to the action of the pressers and borne thereby to the sewing machine), the translating organ (activated by the actuator 22 and having a C-shaped section) is aligned with the two supports 16 of the tubes and engages a pin 16a located above each support 16; in this way the activation of the actuator 22 causes the translation, selectively forwards and backwards - of the translating organ and, with it, the two supports (and thus any pair of blades connected by the respective support 16).

Figures 6, 7, 8 and 9 show an embodiment of the blocking and transport device 6, the movement means 9 and the positioning means 20. Also visible are the lever mechanisms associated to each presser and thanks to which the soliciting of the actuator 1 1 is transmitted to the foil, controlling the deformation thereof. The blocking and transport device 6 preferably comprises a pad 25 positioned superiorly of the tubes 4 and mobile between a raised position, in which it does not cooperate with the semi-finished piece, and a lowered position, in which it enters into contact superiorly with the toes of the semi-finished piece enveloped on the blades (in the advanced position) of a pair of tubes. The pad 25 is configured such as to be brought into the lowered position when the plate is in the raised configuration, in such a way as to block the toes of the semi-finished piece against the plate, and to remain in the lowered configuration up to when the pressers, in the curved configuration, are brought into the lowered position thereof. The pad 25 is further configured such as to return into the raised position before the pressers, in the lowered position, pass into the straight configuration.

The toe-closer machine preferably comprises a pair of blocking organs 26 located at a positioning station of the toe-closer machine, each blocking organ being mobile between an active position, in which it presses on a portion of a respective tube of the pair of tubes in such a way as to block a portion, interposed between the toe and the body trunk part, of a respective leg of the semi-finished piece enveloped on the tube, and an inactive position, in which it is distanced from the tube and does not interfere with the respective leg, each of the blocking organs 26 being configured such as to be brought into the active position when the stitches of the semi-finished piece are blocked between the pressers and the plate and the blades of the tubes return into the retracted position and/or up to when the pressers, in the curved configuration, are in the lowered position, and/or being configured such as to be brought into the deactivated position in the remaining part of the machine cycle.

The blocking organs 26 are preferably positioned in the active and inactive positions thereof in a substantially alike way, or simultaneously, to the positioning of the pad 25 respectively in the lowered and raised positions. The blocking organ and the pad overall provide two blocking points of a leg of the tights, useful for maintaining it in a fixed position while the pressers are in a lowered position and pass from the curved configuration to the straight configuration; in particular, the blocking organ exerts a slight pressure on the leg upstream of the blocked portion of the pressers, while the pad exerts a slight pressure on the leg downstream of the blocked portion of the pressers. in this way the force exerted by the pressers during the passage from the curved configuration to the straight configuration determines a "pulling" of the leg, which causes a sliding of the fabric and a possible loss of the desired progression for the curvature.

A process for producing tights, according to the present invention, comprises one or more of the following steps of:

- reciprocally joining, by means of a line-closer machine, a pair of tubular textile articles such as to form a semi-finished piece having a trunk part and two legs with open toes;

- transferring, by means of a transfer device, the semi-finished piece from the line-closer machine to a pair of tubes of a toe-closer machine, such that each leg of the semi-finished piece is enveloped on a respective tube, each tube being provided with two blades in a retracted position;

- bringing the two blades of each tube of the pair of tubes into an advanced position such as to position the toes of the legs of the semi-finished piece beyond the longitudinal extension of the tubes, keeping them enveloped on the blades;

- predisposing a blocking and transport device structured to be operatively activatable on the toes of the legs of a semi-finished piece in order to block them in a predetermined configuration and transport them to a sewing machine for the toes to be closed by means of carrying out a stitching having a predetermined progression, the blocking and transport device comprising a plate and at least a pair of pressers;

- positioning the plate in a raised position, in which it enters into contact inferiorly with the toes of the semi-finished piece enveloped on the blades of the tubes;

- positioning the two pressers of the pairs of pressers in a raised position, in which they do not contact the stitches of the semi-finished piece, and bringing them, preferably together, into a curved position,

- positioning the two pressers in a lowered position, in which they each block a portion of a respective toe of the semi-finished piece, pressing the portion on the underlying plate, such that the blocked portion of the respective toe assumes a curved shape, the curved shape being substantially corresponding to the predetermined progression of the stitching;

- returning the blades into the retracted position;

- maintaining the pressers in the lowered position and/or the plate in the raised position, bringing the two pressers of the pair of pressers, preferably together, into a straight configuration, making the blocked portions of the toes take on a linear shape;

- predisposing movement means configured such as to move the pair of pressers between a first position, in which the pressers cooperate with the pair of tubes bearing the semi-finished piece, and a second position, in which the pressers subject the toes to a sewing machine; - positioning, by means of the movement means, the pair of pressers, bringing the toes of the semi-finished piece into the second stitching position;

- sewing, using a sewing machine of the toe-closer machine, the toes of the legs of the semi-finished piece, such as to obtain a complete garment of tights, the sewing having the predetermined progression;

- on terminating the sewing of the stitches, unloading the semi-finished piece from the respect pair of tubes, positioning, using the movement means, the pair of pressers in the first position, bringing the pair of pressers into the raised position and bringing the plate into the lowered position.

The steps of advancing the blades and blocking the toes by the pressers are done with the second carousel stationary (i.e. with a precise "machine halt"). During the steps of translation of the pressers (with the respective toes pressed on the underlying plate) towards the sewing machine and the actual sewing, the second carousel preferably performs a rotation so as to follow the sewing (i.e. to cause the toes to slide, blocked by the pressers, to the sewing machine) and at the same time prepares a new pair of tubes of the toe-closer to receive the loading of a new semi-finished workpiece from the line-closer.

The further aspects of the sewing process of the trunk, the transfer of the semifinished workpieces and/or the sewing of the toes, not described in detail in the present description and not deriving from special characteristics of the apparatus as described above, are to be considered of a known type.

The invention as it is conceived is susceptible to numerous modifications and variants, all falling within the scope of the inventive concept, and the components cited can be replaced by other technically-equivalent elements. The invention attains important advantages.

Primarily the invention enables obviating at least some of the drawbacks of the prior art.

The invention further enables realizing tights of high quality and substantially free of imperfections.

The invention further obtains sewing of the toes of tights having a predetermined progression and/or a precise shape and/or specific dimensions, and/or enables easily modifying the parameter on the basis of the type of production.

The invention further enables reducing production waste and/or obtaining a high degree of precision and/or repeatability of the characteristics of the tights produced.

The invention further enables producing tights simply and/or rapidly and/or automatically. The invention is further simple and/or sturdy and/or economical to realize.